Centre-ground voters still hold the key to winning elections, former prime minister Tony Blair has said.

In comments which will be seen as a warning to Labour over its move to the left under Jeremy Corbyn, the party’s former leader warned against populist policies which play to voters’ anger.

And he admitted that he felt “a little bit of anxiety” over the upcoming presidential election in the USA, which has seen an upsurge in support for candidates from the right and left of the political spectrum, including Donald Trump and Bernie Sanders.

Asked whether he believed the kind of “centrist” politics he represented was now dead, Mr Blair told Fox Business: “No, but I think if the centre is not muscular then the extremes gain.

“That’s why centrist politics should not be a soggy compromise between left and right.

“It’s got to have a series of tough policies that meet the concerns and anxieties of people but do so in a way that’s sensible. A lot of the populism, left and right, is very good at playing to people’s anger, but it doesn’t actually provide answers. And in the end it’s answers that create the right type of future for our countries. You see this in the US, you see it in the UK, you see it all over.”

Mr Blair added: “The only thing I feel in the end is that, when you look at the election results, the broad public - who in the end decide the result in a democracy - I still think that they are located more in the centre than people realise.”

The former PM said it would not be “sensible” for the UK to ban Mr Trump from visiting the country over his comments about Muslims, as a petition discussed this week in Parliament demanded. You can get petitions of half a million people on virtually anything nowadays,” said Mr Blair.

“However much I may disagree with what he says, I don’t think that would be a sensible course of action to take.

“We’re all watching your election in the US with a lot of interest and I’d say also a little bit of anxiety.

“It certainly makes for interesting viewing.”

Mr Trump remains the Republicans frontrunner ahead of the first primary, due to take place on February 1.